Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “PULMONARY CIRCULATION”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 721 records · Page 40Linked to original sources
PubMed1985

[Comparison of vascular width and accuracy in the subjective assessment of pulmonary circulation in the roentgen picture of children with left-right shunts].

The authors established a comparative relationship between accuracy of measurement of pulmonary flow and extent of vascular widening in 72 children with Left-Right shunt vitiae; this accuracy of pulmonary flow measurement had been subjectively estimated by 4 investigators without knowing the diagnosis and in comparison to the haemodynamic values (percentage of correct findings). The following procedure was adopted: In a control group of 143 healthy children, we first determined the vascular diameter of the right descending pulmonary artery, of the right upper lobal vein, and of the peripheral vessels in the upper and lower pulmonary fields, at an accurately defined distance from the point of the hilus, and compared with the vascular diameters of the children with left-right shunt, employing the method of discrimination analysis. Comparison of the judgement by the 4 investigators with the degree of increase of the vascular diameters showed an accuracy of 65-100% if the right descending pulmonary artery became wider by 2.6 mm, and an accuracy of 79-95% if the mean vascular width in the right upper field increased by 0.7 mm. The accuracy was 83-94% if the mean vascular width in the right lower field increased by 0.6 mm. Statistical studies also showed that the judgement of the 4 investigators was influenced by different vessels.

Adolescent↗
PubMed1982

Effect of hypoxia on adaptation of the pulmonary circulation to extra-uterine life in the pig.

Pigs were exposed to hypoxia for 2 to 5 days, at ages ranging from bith to 2 weeks. The effect of hypoxia on structural adaptation of the pulmonary arterial circulation to extra-uterine life was studied by applying quantitative morphometric techniques to the injected autopsy lung specimens. In animals exposed to hypoxia from birth, the reduction in arterial muscularity, and increase in size and number which normally takes place after, began to occur, but the process was arrested by exposure to hypoxia which with increase in exposure time caused a secondary increase in muscularity. In animals allowed to adapt fully to extra-uterine life and first exposed at 14 days, increase in muscularity as shown by an increase in wall thickness and extension of muscle into smaller and more peripheral arteries than is normal, was secondary to the hypoxic insult and similar to that reported in adults of other species. Animals exposed a between 2 and 7 days of age showed an intermediate response, failure to adapt normally plus a secondary increase in muscularity. Right ventricular hypertrophy developed in all animals. The studies emphasise the vulnerability of the newborn pulmonary circulation to hypoxia and the rapidity with which structural change occurs.

Adaptation, Physiological↗
PubMed1982

Crotalaria-induced pulmonary hypertension. Uptake of 3H-thymidine by the cells of the pulmonary circulation and alveolar walls.

Feeding with Crotalaria spectabilis seeds induces structural changes in the pulmonary arterial circulation characteristic of pulmonary hypertension: increased medial and adventitial thickness, the appearance of muscle in smaller arteries than normal, and reduction in the number of peripheral arteries. By autoradiographic techniques, after injection of 3H-thymidine into rats fed Crotalaria for 3, 7, 14, 21, 28, or 35 days, the contribution of hyperplasia to these changes has been assessed at two levels of the pulmonary artery--the hilum and the periphery. In the hilar pulmonary artery, a biphasic increase in labeling index (LI) is seen in each cell type. After 3 days of feeding, the medial smooth muscle cells show a slight but significant increase (1.5 times the control value), and, after 7 days, so do the adventitial fibroblasts (3 x) and the endothelial cells (EC) (2 x). After 14 days LI for all three cell types is again at control values, but after 21 days (wall thickness is no increased) each cell type shows at least a fivefold increase; by 35 days all are again near control levels. In the intra-acinar region, by 14 days, "newly" muscularized arteries are identified and increase in number and proportion up to 35 days; 3H-thymidine uptake is not evident in this cell type until 35 days have passed. The ECs of these arteries, however, show a striking increase in LI after 14 days as do those of the alveolar capillaries. The ECs of the intra-acinar veins show a biphasic response being increased after 7, 28, and 35 days. The present study has shown that Crotalaria ingestion induces hyperplasia and hypertrophy of pulmonary arterial cells at pre- and intra-acinar levels. The early increase in LI probably represents a response to the original cell injury, the later changes, a response to continuing damage or, in part, adaptation to the pulmonary hypertension now present.

Animals↗